Chris Doucette, QMI Agency

TORONTO - Investigators are set to announce new charges in the summer’s deadly gang shootout at an outdoor party on Danzig St. — the worst mass shooting in the city’s history.

Toronto Police will hold a press conference at headquarters on Thursday at 2 p.m. to announce advancements in the investigation into the July 16 gun battle that killed two innocent bystanders and wounded 23 others, including a toddler.

A source said Wednesday that investigators will reveal additional charges have been laid in the shooting that claimed the lives of Joshua Yasay, 23, and Shyanne Charles, 14.

While there have been several arrests in connection with the bloodbath at the east end housing complex, located near Morningside Rd. and Lawrence Ave. E., only one person has been charged with murder.

Staff-Insp. Greg McLane, who heads up the homicide unit, revealed earlier this month that Shaquan ‘Bam Bam’ Mesquito was charged with one count of attempted murder, 23 counts of aggravated assault and one count of reckless discharge of a firearm.

The 18-year-old was already locked up. He was arrested within days of the Danzig shooting for firearms offences and uttering threats.

When McLane made that announcement, he also said the investigation was “far from over” and he released composite drawings of two men investigators were trying to identify.

As many as 150 people attended the outdoor barbecue on Danzig and investigators allege members of the notorious Galloway Boys street gang “took ownership” of the party.

Police believe Mesquito, an alleged member of the rival Malvern Crew, was refused entry into the party.

McLane has alleged that Mesquito left the housing complex, called some of his fellow gang members and then returned “to seek revenge.”